1. Field of the Invention
The invention relates in general to a method and associated apparatus for signal control, and more particularly to a method and associated apparatus for clock-data edge alignment.
2. Description of the Related Art
FIG. 1 shows a schematic diagram of a conventional signal transmitter. In the transmitter, a digital signal D in a KHz level is converted by a digital-to-analog converter (DAC) 102 into an analog signal A, which is then inputted into a mixer 110. Through a local oscillation (LO) signal generated by a local oscillator 112, the analog signal A inputted into the mixer 110 is up-converted to a radio-frequency (RF) signal in a level of GHz, which is then amplified by a high-output frequency amplifier 114 and outputted as an amplified RF signal ARF.
A radio-frequency digital-to-analog converter (RFDAC), or referred to as a digital power amplifier, is now available for replacing functions of the above signal transmitter to directly generate a large-power RF signal. FIG. 2 shows a schematic diagram of an RFDAC. An RFDAC 200 includes an input as an N-bit digital signal D bus and an LO input. All input signals including the N-bit digital signal D and the LO signal are fundamentally GHz signals, according to which the RFDAC 200 is capable of generating an RF signal.
In addition to having the same frequency, signal edges between all of the input signals also need to be aligned to prevent output power degradation and noise increase in the RFDAC 200. Therefore, there is a need for a solution capable of effectively aligning signal edges between the input signals.